This invention relates to therapeutic traction devices and more particularly to a chair that fixes the pelvic girdle and applies traction to the spine through lifting of the shoulder under the direct control of the patient.
In the treatment of orthopedic disorders of the back and spine, it has long been recognized that relief of pain and long term benefit often results from placing the spine in traction or extension. A well known method is to strap a harness about the pelvis and another harness about the thorax. These are then pulled in opposite directions by weights on pulleys, springs, motors and the like. Apparatus of this type is exemplified by the U.S. Pat. Nos. 4,466,427, 4,356,816 and 4,664,101. These devices are awkward and time-consuming to apply. They are especially awkward for females, because the breasts interfere.
U.S. Pat. No. 4,688,557 issued Aug. 25, 1987 to Bradstreet discloses a chair with arm supports extending from the backrest and under the armpits. The seat adjustably drops down so that the weight of the body is supported only by the armrests and tension on the spine is determined by the body weight.
U.S. Pat. No. 3,675,646 issued Jul. 11, 1972 to the Applicant discloses a chair with a housing for engaging the hips and another housing for engaging the armpits. The housings are supported on parallel posts with racks and the housings are adjusted vertically by crank-operated worm gears engaging the racks. The cranks must be operated from the rear, there are no means of locking the housings at a particular level, and the mechanism is costly to produce.
It would be useful to produce a chair that would hold the pelvic girdle in place and pull upward on the shoulder girdle that would be easily adjusted and operated by the patient, and that would be simple and economical to manufacture.